Occupant Dynamics During Crash Avoidance Maneuvers

Technical Report FinalA test-track study was conducted to assess the effects of initial posture and position on the head motions of front-seat passengers in abrupt vehicle maneuvers. A pilot study with 12 participants was conducted in a sedan, a minivan, and a pickup truck to assess whether head excursions differed across vehicles. Each participant experienced two abrupt braking events, two lane changes, and turn-and-brake maneuvers. Peak vehicle accelerations were about 1 g and 0.7 g in the braking and lane-change events, respectively. Head position was tracked using a custom, semi-automated system that uses a single depth camera. Head center of gravity (CG) location was estimated from landmarks identified on a three-dimensional scan of the participant’s head and face. Forward head excursion was slightly smaller in the passenger car than in the other two vehicles. No explanation for this finding was apparent; the vehicle kinematics were similar. A larger study was then conducted using a passenger sedan and an SUV. A total of 90 men and women with a wide range of age and body size were assigned to test-condition blocks that addressed a variety of initial conditions. The factors investigated were seat position, foot placement, seat back recline angle, retractor locking, vehicle differences, and the effects of leaning inboard on the console armrest or leaning forward while reaching. Each participant experienced two braking events, a right-going lane change, a left-going lane change, and a turn-and-brake maneuver. The two vehicles performed similarly, and the acceleration profiles were similar to both the pilot study and a 2018 study at the same facility. Greater forward head excursion relative to the seat was observed when the seat was further rearward or reclined, or the feet were placed flat rather than resting on the heels. No difference in forward excursion was noted across vehicles. Forward leaning reduced forward head excursion during braking events, but the head position was more forward than when starting from a standard posture. Younger participants exhibited slightly larger forward excursions, but overall anthropometric effects were small. Forward lean produced much larger lateral excursions than the standard posture. Recline reduced lateral excursions, as did resting the feet on the heels rather than flat on the soles. Greater outboard excursion was observed in the SUV during the left lane change, possibly because greater space was available than in the sedan. Higher BMI and younger age were associated with slightly larger lateral excursions in some conditions, but anthropometric effects were small compared with the effects of test conditions. A functional regression analysis of head CG trajectories on the primary axes of motion was conducted. The results provide insight into the effects of test and occupant variables on head motion. Parametric corridors were developed that can be used to tune and validate computational models of occupant responses in pre-crash maneuvers. Overall, the results suggest that a wide range of occupant head locations can be produced by abrupt vehicle maneuvers. More research is needed to assess the robustness of occupant protection systems to this wide range of postures.National Highway Traffic Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/168421/1/UMTRI-2020-10 final.pdfDescription of UMTRI-2020-10 final.pdf : Technical Report Fina

Human motion simulation for vehicle and workplace design

Digital Human Models (DHMs) are fast becoming an effective tool for performing proactive ergonomics analysis and design. DHM software, such as Jack, SAFEWORK, RAMSIS, SAMMIE, and the UM 3DSSP, are meant to assist a designer early in a product development process, when he or she is attempting to improve the physical design of vehicle interiors and manufacturing workplaces. To become even more effective in meeting such a goal, it is proposed that future DHMs must include valid posture and motion prediction models for various populations. It is argued in this article that existing posture and motion prediction models now used in DHMs must be based on real motion data to assure validity for complex dynamic task simulations. It is further proposed that if valid human posture and motion prediction models are developed, these can be combined with psychophysical and biomechanical models to provide a very powerful tool for predicting dynamic human performance and population specific limitations. © 2007 Wiley Periodicals, Inc. Hum Factors Man 17: 475–484, 2007.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56152/1/20087_ftp.pd

The ergonomics and design of an inclusive best-fit solution to workbenches

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.In a time when the developed world, is trying to reduce the human and economic costs of musculo-skeletal disorders (MSDs), any contribution to such an endeavour would be welcome. These economic costs are estimated to be in the tens of billions of Euro in the EU countries and similarly in the USA, the cost in human pain has not been measured. It may surprise many that in spite of all the advancements in science and technology, that two generations of people, who are very significantly taller than the people of a century ago, are still working in industry and in education at benches, which have not changed, either in height or design in centuries. Some, like wheelchair users do not have the opportunity to work at a bench at all. At the outset this research project, had the primary objective of determining an ergonomic best-fit, for a broad range of users of workbenches. These included the young school going population (12-13 year olds), the senior students (16 plus years old), adults, and a cohort of surrogate wheelchair users. The research also endeavoured to determine if adolescents, who were of the same stature as adults, had the same workbench ergonomics requirements. The secondary objective, which was completely dependant on the first, was to design a bench, which would suit the ergonomic requirements of this diverse group. The research has identified the best-fit workbench heights for the total cohort, while recognising the individual differences in relation to bench height ergonomics, for each of the sub-groups tested. The findings of the research have shown, that using surrogate wheelchair users to determine ergonomic data for this type of activity is fully justified. In combining the raw data for a similar number of wheelchair users, a best-fit bench height has been confirmed at 100 mm above knee height. There are no significant differences between the ergonomic requirements for males and females at workbenches. Body part discomfort has been reduced significantly, for the wheelchair users, at the identified height and endurance has been extended. Importantly the career options for wheelchair users have been extended, empowering them to make broader career choices. The outcomes of the research relating to three groups making up the able-bodied cohort have shown that an ergonomic best-fits possible, which suits the needs of this diverse group. A height of 150 mm under elbow height has been identified as best-fit, and this reduces the discomfort considerably while extending endurance. Robust working heights have been identified, but the female working heights at workbenches, are not as robust as for the males. For all groups it has been shown that bench height has a significant effect on body part discomfort and endurance, and while there were differences in efficiency, which were not quite significant, it is suggested that working in an ergonomically compromising position must, in the long term, in addition to increasing the risk of MSDs, likely also influence productivity, and quality of work. An inclusive test-workbench has been designed and built which satisfies the ergonomic needs of the diverse user group described above

Vehicle ergonomics and older drivers

There is a growing population of older people around the world and the population of older drivers is increasing in parallel. UK government figures in 2012 reported that there were more than 15 million people with a driving license aged over 60; more than 1 million of these were over 80. The aim of this thesis is to determine the requirements of older users for an improved driving experience leading to recommendations for the automotive industry. Initially it was necessary to understand some of the key issues concerning the driving experiences of older drivers; therefore a questionnaire survey of drivers of all ages (n=903) was conducted supplemented by interviews with drivers aged ≥ 65 years (n=15). Areas covered included: musculoskeletal symptoms, the vehicle seat, driving performance and driving behaviour. Respondents reported that they were dissatisfied with adjusting specific seat features, for example the head rest height and distance from the head; females reported more difficulty than males. Reaching and pulling the boot door down to close was difficult for 12% of older females. Older males and females also reported more difficulties with parallel parking and driving on a foggy day than younger drivers (p<0.01). Nearly half of the sample (47%) reported that other drivers lights restrict their vision when driving at night. An in depth study was conducted to compare participants own vehicle (familiar) and a test vehicle (unfamiliar) to understand how design of the vehicle cab impacts on posture, comfort, health and wellbeing in older drivers (n=47, ≥50 years). The study involved functional performance assessments, seat set-up process evaluation (observations and postural analysis), ergonomics and emotional design based evaluations of car seat controls. Many issues were identified related to the seat controls such as operating, accessing, reaching and finding, particularly for the head rest height and lumbar support adjustments. Approximately 40% of the participants had difficulty turning their head and body around to adjust the head rest height, and the majority of these were over 80. This led to a series of workshops (including a participatory design exercise) with 18 participants (4 groups, ≥ 65 years).The aim was to explore the optimum positioning and operation of controls for older drivers. This research has provided foundational data and makes design recommendations for the automotive industry with a focus on making seat controls more inclusive (operation, location, type, size, colour and materials) and meet the requirements of older drivers

Gender Differences and Cockpit Design

The design project reported in this paper examined female pilots’ experiences with how well or poorly cockpit design allowed them to safely accomplish their flying missions. The general aviation aircraft cockpit is not designed for female pilots, often causing them to find ways to adapt to the cockpit in order to operate the aircraft safely. Two primary focal areas for adaptations address issues with accessibility of controls and “viewability” inside and outside the cockpit. The design team used a Situation Awareness-Oriented Interface Design (SAOD) approach in preparing cockpit design recommendations for general aviation aircraft that would accommodate female pilots

Workforce challenges: 'inclusive design' for organizational sustainability

Today's challenge for workforce management lies in providing a healthy, safe and productive working culture where people are valued, empowered and respected. Workforce diversity is becoming an essential aspect of the global workforce, and ageing is the most prominent and significant factor in this regard. Diversity brings many opportunities and challenges, as workers with different backgrounds, cultures, working attitudes, behaviours and age work together, and in future, the key to organizational effectiveness and sustainability will heavily depend on developing and sustaining inclusive work environments where people with their differences can co-exist safely and productively. Manufacturing organizations expect the highest levels of productivity and quality, but unfortunately the manufacturing system design process does not take into account human variability issues caused by age, skill, experience, attitude towards work etc. This thesis focuses on proposing an inclusive design methodology to address the design needs of a broader range of the population. However, the promotion and implementation of an inclusive design method is challenging due to the lack of relevant data and lack of relevant tools and methods to help designers. This research aims to support the inclusive design process by providing relevant data and developing new design methodologies. The inclusive design methodology suggested in this thesis is a three step approach for achieving a safe and sustainable work environment for workers, with special concern for older workers. The methodology is based on the provision of relevant human capabilities data, the capture and analysis of difference in human behaviour and the use of this knowledge in a digital human modelling tool. The research is focused on manual assembly through a case study in the furniture manufacturing industry and joint mobility data from a wide-ranging population has been analysed and the task performing strategies and behaviours of workers with different levels of skills have been recorded and analysed. It has been shown that joint mobility significantly decreases with age and disability and that skilful workers are likely to adopt safer and more productive working strategies. A digital human modelling based inclusive design strategy was found to be useful in addressing the design needs of older workers performing manufacturing assembly activities. This strategy validates the concept of using human capabilities data for assessing the level of acceptability of any adopted strategy for older workers, and suggests that the strategies adopted by skilful workers are more likely to be equally acceptable for older and younger workers keeping in view differences in their joint mobility. The overall purpose of this thesis is to present a road map towards the promotion and implementation of the inclusive design method for addressing workforce challenges and in future the same strategies might be implemented within a variety of other industrial applications. The proposed three step inclusive design methodology and getting a reasonable understanding of human variability issues along with the use of human capabilities data (joint mobility in this case) in a human modelling system for design assessment at a pre-design stage can be considered as the major contributions of this research

Anthropometric characteristics of roadside auto-mechanics: a case study

The study evaluated the relevant/corresponding anthropometric characteristics of the people involved in engine-repair activities. The study was carried out on the selected roadside auto-engine repairers along Lagos-Ibadan express way, in Nigeria. This was with a view to providing ergonomic design data for optimal working condition among this set of workforce and redesigning the mechanics inspection-pit. Material and methods: The static and the functional anthropometric characteristics of the mechanics were measured. The data obtained from 110 auto-mechanics, randomly selected, were employed to evaluate efficient design parameter for roadside workstations. Results: The results indicated that inspection-pit is about 1626 mm deep; seat height ranges between 375 mm and 405 mm; optimal work posture sitting is between 483 mm and 622 mm. Conclusions: Adopting the data presented in this paper in optimizing the auto-mechanics working conditions for effective workplace comfort and productivity among the roadside auto-mechanics in Nigeria will be of immense advantage

Pre-Crash and In-Crash Car Occupant Safety Assessment

Tens of millions are annually injured in Road Traffic Accidents (RTAs) worldwide, while the estimated number of RTA fatalities amounted to 1.35 million in 2016. In Europe, car occupants hold the largest share (48%) of fatalities among all road users. The high fatality and injury numbers motivate the work of enhancing road traffic safety. A holistic safety assessment approach, considering both the pre- and the in-crash phase of a crash, has the potential to enhance real-world occupant protection evaluation, as well as facilitate the development of effective countermeasures. In standardized car occupant safety assessments, occupant surrogates of standardized anthropometries are employed in standardized postures, with the seat adjusted to a single predefined position. The vehicle is then subjected to predefined crash configurations with meticulously described impact points and angles. In contrast, real-world traffic crashes involve occupants of different shapes and sizes, who adjust the position of the seat and their posture on the seat differently, and the vehicles are subjected to diverse crash configurations (multiple impact locations, impact directions, and speed combinations). The overall aim of this thesis is to develop and apply methods, spanning from the pre-crash to the in-crash phase, capable of evaluating and enhancing the real-world occupant protection of future vehicles.The introduction of crash-avoidance systems has the potential to alter the crash configurations that future vehicles will be exposed to. A method for predicting crash configurations has been developed in this thesis and applied to highway driving, and urban intersection crashes. Performing counterfactual simulations of digitized real-world crashes, with and without the addition of a conceptual Automatic Emergency Braking system, provides a prediction of the remaining crashes. The use of a novel crash configuration definition, along with a purpose-designed clustering method, facilitates the reduction of the number of predicted crash configurations without sacrificing coverage of the diverse real-world situations. Three predicted crash configurations, representative of urban intersection crashes, were further analyzed during the in-crash phase. A Human Body Model was positioned in a wide range of occupant postures identified from the literature. The findings suggest that the lower extremity postures had the largest overall influence on the lower extremities, pelvis, and whole-body responses for all crash configurations. In the evaluated side-impacts, leaning the torso in the coronal plane affected the torso and head kinematics by changing the interaction with the vehicle’s interior. Additionally, in far-side impacts supporting the occupant’s arm on the center console resulted in increased torso excursions. Moreover, the upper extremity responses were consistently sensitive to posture variations of all body regions

An approach to vehicle design: in-depth audit to understand the needs of older drivers

The population of older people continues to increase around the world, and this trend is expected to continue; the population of older drivers is increasing accordingly. January 2012 figures from the DVLA in the UK stated that there were more than 15 million drivers aged over 60; more than 1 million drivers were aged over 80. There is a need for specific research tools to understand and capture how all users interact with features in the vehicle cabin e.g. controls and tasks, including the specific needs of the increasingly older driving population. This paper describes an in-depth audit that was conducted to understand how design of the vehicle cabin impacts on comfort, posture, usability, health and wellbeing in older drivers. The sample involved 47 drivers (38% female, 62% male). The age distribution was: 50–64 (n = 12), 65–79 (n = 20), and those 80 and over (n = 15). The methodology included tools to capture user experience in the vehicle cabin and functional performance tests relevant to specific driving tasks. It is shown that drivers' physical capabilities reduce with age and that there are associated difficulties in setting up an optimal driving position such that some controls cannot be operated as intended, and many adapt their driving cabins. The cabin set-up process consistently began with setting up the seat and finished with operation of the seat belt